SecureGmail encrypts and decrypts messages you send via Gmail. This happens on your computer, so unencrypted text never arrives on Google servers. It is a very useful plugin (works only on Google Chrome and Apple's Safari) if you want to be sure that only the final recipient will read your email and not companies, governments, etc.).
The project is very reliable as it is open source. Community involvement guarantees transparency in the code but also helps identify potential bugs. The whole project is in GitHub for anyone who wants to control the code, and according to the developers every tweak you have to suggest is always welcome.
How safe is it?
SecureGmail uses symmetric encryption to encrypt and decrypt each message. The password decided by the user is also known to the recipient.
It's only as secure as your password (short passwords provide minimal security). Remember you should never share codes via email or IM. Use as long as you like for encryption.
SecureGmail uses an open source JS librarycase of cryptography from Stanford available here as well as in Github.
The plugin is compatible with any account σας στο Gmail και μπορείτε να το χρησιμοποιήσετε σε πολλούς λογαριασμούς ταυτόχρονα. Λειτουργεί άψογα σε προσωπικούς λογαριασμούς του Gmail ή σε λογαριασμούς που παρέχονται από τον company your, the school, or your organization through Google Apps.
Download the Chrome plugin:
